There are false teachings advocated in secret by people who are either deceived by a false spirit or willingly sinful. These false teachings include such notions as: It is not a sin to have sexual relations outside of marriage if both participants are unmarried. This, of course, is false, and the scriptures condemn such fornication and sexual impurity. “As touching the gentiles who believe, we have written and concluded that they … keep themselves from things offered to idols, … and from fornication.” (NC Acts 12:9) “Now the body is not for fornication, but for the Lord, and the Lord for the body. And God has both raised up the Lord and will also raise up us by his own power. Do you not know that your bodies are the members of Christ? Shall I then take the members of Christ and make them the members of a harlot? God forbid. What? Do you not know that he who is joined to a harlot is one body? For two, says he, shall be one flesh. But he that is joined unto the Lord is one spirit. Flee fornication. Every sin that a man commits is against the body of Christ, and he who commits fornication sins against his own body.” (NC 1 Cor 1:23) “Now the works of the flesh are manifest, which are: adultery, fornication, uncleanness, lasciviousness, idolatry, witchcraft, hatred, variance, emulations, wrath, strife, seditions, heresies, envyings, murders, drunkenness, revelings, and such like; of the which I tell you, as I have also told in time past, that they who do such things shall not inherit the kingdom of God.” (NC Gal. 1:21)
Fornication will prevent you from inheriting the kingdom of God. It is as offensive as adultery, and often condemned in the same statement alongside adultery.
Those who teach this evil often conceal their teachings from the public, choosing to do so in secret. They teach it secretly because they are ashamed of this false, repugnant idea. Teaching in secret is an indication they recognize what they teach is false.
By concealing their sin, they hope their lies will protect them. The scriptures make it clear this will do them no good. “Last of all, these all are they who will not be gathered with the saints, to be caught up unto the church of the Firstborn and received into the Cloud. These are they who are liars, and sorcerers, and adulterers, and whoremongers, and whoever loves and makes a lie. These are they who suffer the wrath of God on the earth. These are they who suffer the vengeance of Eternal fire. These are they who are cast down to Hell and suffer the wrath of Almighty God” (T&C 69:27).
Part of the success of such false teachings comes from carefully keeping it hidden. Hiding their false teachings only makes them liars who love and make a lie to advance their adultery and whoredoms.
From all such teachings and teachers you should flee. Their teachings are calculated only to corrupt, deceive and destroy.